TOMOGRAFíA SíSMICA 3D DEL SECTOR DE CúCUTA, COLOMBIA

a 3d seismic tomography for cúcua area was done, by using p and s waves arrival times from local and regional earthquakes. a high-vp zone e-w, between 80-140km depth, going down toward w, is related with the subduction slab of caribbean plate. the collision of these plate with south america plate is the source of bucaramanga seismic nest, which is located between 100 and 160km depth. other high-vp zone to the south, between 20 and 50km depth, seems to correspond with the seismically active bucaramanga fault. a low-vp zone (0-30km depth) starting to the w of cúcuta, and ending at the limit of the study area was found; this low-vp zone is associated with the eastern part of boconó fault, and with the santander massif limit to the west. the caribbean plate seems to exhibit a subduction plane in horse-shoe shape, deeping to the south, with an angle between 40 and 45 degres.